This Rhyacophilan Caddisfly is currently ranked a "SNR" a Potential Species of Concern in MT and at risk because of very limited and/or potentially declining population numbers, range and/or habitat, making it vulnerable to extirpation in the state. Limited sites with small populations, and the species is difficult to identify without adult specimens. Only 2 records for Montana

General Description

Rhyacophila oreia is a free-living caddisfly (no case) that is a regional endemic only known from a limited area in Wyoming, Idaho and now Motnana. Ecological data for U.S. states and Canadian provinces is known to be incomplete or has not been reviewed for this taxon. Although, given it's locality information for Montana, this species like others in the oreia species group, prefer small, fast-flowing cold forested streams.

(Observations spanning multiple months or years are excluded from time charts)

Habitat

This Rhyacophila seems restricted to spring-influenced cold-forested, streams in the forested streams of western Montana

Food Habits

Most Rhyacophila species are predators feeding mostly on aquatic insects, especially midges and blackflies

Management

Limited data and the inability to identify larval collections has lead to a low global rank. Distribution data for U.S. states and Canadian provinces is known to be incomplete or has not been reviewed for this taxon.

Threats or Limiting Factors

Specific threats to Montana populations of R. oreia would include mismanagement of forested riparian areas, including sediment and temperature increases associated with road building and timber harvests not following BMPs. In general, cold-stenothermic (cold-water specialists) invertebrate populations are affected by changes to aquatic habitat, such as alteration of flow patterns, streambed substrate, thermal characteristics, and water quality. Alteration and degradation of riparian and aquatic habitat is the primary concern for Montana populations.